No classloading in TypeUtil.isMap method

See: https://www.pivotaltracker.com/story/show/167917595

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/metadata/PropertyInfo.java

@@ -145,7 +145,7 @@ public class PropertyInfo {
 
 	public HintProvider getHints(TypeUtil typeUtil) {
 		Type type = TypeParser.parse(this.type);
-		if (TypeUtil.isMap(type)) {
+		if (typeUtil.isMap(type)) {
 			return HintProviders.forMap(keyHints(typeUtil), valueHints(typeUtil), TypeUtil.getDomainType(type));
 		} else if (TypeUtil.isSequencable(type)) {
 			return HintProviders.forAllValueContexts(valueHints(typeUtil));

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/metadata/types/TypeUtil.java

@@ -485,7 +485,7 @@ public class TypeUtil {
 		return type!=null && type.getErasure().endsWith("[]");
 	}
 
-	public static boolean isMap(Type type) {
+	public boolean isMap(Type type) {
 		//Note: to be really correct we should use JDT infrastructure to resolve
 		//type in project classpath instead of using Java reflection.
 		//However, use reflection here is okay assuming types we care about
@@ -493,9 +493,14 @@ public class TypeUtil {
 		//also potentialy be very slow.
 		if (type!=null) {
 			String erasure = type.getErasure();
+			if ("java.util.Map".equals(erasure)) {
+				//quick / easy case. No looking for types and hierarchies required.
+				return true;
+			}
 			try {
-				Class<?> erasureClass = Class.forName(erasure);
+				IType mapType = findType("java.util.Map");
-				return Map.class.isAssignableFrom(erasureClass);
+				IType erasureType = findType(erasure);
+				return isAssignableFrom(mapType, erasureType);
 			} catch (Exception e) {
 				//type not resolveable
 			}
@@ -503,6 +508,36 @@ public class TypeUtil {
 		return false;
 	}
 
+	private boolean isAssignableFrom(IType mapType, IType erasureType) {
+		Set<String> seen = new HashSet<>();
+		return searchSuperTypes(seen, erasureType, mapType.getFullyQualifiedName());
+	}
+
+
+	private boolean searchSuperTypes(Set<String> seen, IType searchIn, String fqTargetType) {
+		if (searchIn!=null) {
+			String fqName = searchIn.getFullyQualifiedName();
+			if (fqName.equals(fqTargetType)) {
+				return true;
+			}
+			if (seen.add(fqName)) {
+				for (String itfName : searchIn.getSuperInterfaceNames()) {
+					IType itf = findType(itfName);
+					if (searchSuperTypes(seen, itf, fqTargetType)) {
+						return true;
+					}
+				}
+				String klassName = searchIn.getSuperclassName();
+				IType klass = findType(klassName);
+				if (searchSuperTypes(seen, klass, fqTargetType)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
+
 	/**
 	 * Get domain type for a map or list generic type.
 	 */
@@ -966,9 +1001,9 @@ public class TypeUtil {
 	 * List<List<List<String>>> -> 2
 	 * Map<*,List<String>> -> 2
 	 */
-	public static int getDimensionality(Type type) {
+	public int getDimensionality(Type type) {
 		int dim = 0;
-		while (isSequencable(type) || isMap(type)) {
+		while (isSequencable(type) || this.isMap(type)) {
 			dim++;
 			type = getDomainType(type);
 		}

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/properties/reconcile/PropertyNavigator.java

@@ -163,7 +163,7 @@ public class PropertyNavigator {
 	 * checked to be 'dotable'.
 	 */
 	private Type dotNavigate(int offset, Type type) {
-		if (TypeUtil.isMap(type)) {
+		if (typeUtil.isMap(type)) {
 			int keyStart = offset+1;
 			Type domainType = TypeUtil.getDomainType(type);
 			int keyEnd = -1;

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/yaml/completions/ApplicationYamlAssistContext.java

@@ -116,7 +116,7 @@ public abstract class ApplicationYamlAssistContext extends AbstractYamlAssistCon
 	protected String appendTextFor(Type type) {
 		//Note that proper indentation after each \n" is added automatically
 		//so the strings created here do not need to contain indentation spaces
-		if (TypeUtil.isMap(type)) {
+		if (typeUtil.isMap(type)) {
 			//ready to enter nested map key on next line
 			return "\n"+YamlIndentUtil.INDENT_STR;
 		} if (TypeUtil.isSequencable(type)) {
@@ -328,7 +328,7 @@ public abstract class ApplicationYamlAssistContext extends AbstractYamlAssistCon
 		@Override
 		public YamlAssistContext traverse(YamlPathSegment s) {
 			if (s.getType()==YamlPathSegmentType.VAL_AT_KEY) {
-				if (TypeUtil.isSequencable(type) || TypeUtil.isMap(type)) {
+				if (TypeUtil.isSequencable(type) || typeUtil.isMap(type)) {
 					return contextWith(s, TypeUtil.getDomainType(type));
 				}
 				String key = s.toPropString();
@@ -632,7 +632,7 @@ public abstract class ApplicationYamlAssistContext extends AbstractYamlAssistCon
 	private static List<IJavaElement> getAllJavaElements(TypeUtil typeUtil, Type parentType, String propName) {
 		if (propName!=null) {
 			Type beanType = parentType;
-			if (TypeUtil.isMap(beanType)) {
+			if (typeUtil.isMap(beanType)) {
 				Type keyType = typeUtil.getKeyType(beanType);
 				if (keyType!=null && typeUtil.isEnum(keyType)) {
 					IField field = typeUtil.getEnumConstant(keyType, propName);

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/yaml/reconcile/ApplicationYamlASTReconciler.java

@@ -224,7 +224,7 @@ public class ApplicationYamlASTReconciler implements YamlASTReconciler {
 		checkForDuplicateKeys(mapping);
 		if (typeUtil.isAtomic(type)) {
 			expectTypeFoundMapping(type, mapping);
-		} else if (TypeUtil.isMap(type) || TypeUtil.isSequencable(type)) {
+		} else if (typeUtil.isMap(type) || TypeUtil.isSequencable(type)) {
 			Type keyType = typeUtil.getKeyType(type);
 			Type valueType = TypeUtil.getDomainType(type);
 			if (keyType!=null) {